Replaceable top lift



Nov. 13, 1962 R. F. PURTELL REPLACEABLE TOP LIFT Filed Dec. 9, 1958 INVENTOR. RAYMOND F. PURTELL mm; J'LNNEY, WITTFR a mwmu FIG. 5

ATTORNEYS United States Patent 3,063,170 REPLACEABLE TOP LIFT Raymond F. Purteil, Nashua, N.H., assignor to Fitz-On Heel Corporation, Manchester, N.H., a corporation of Delaware Filed Dec. 9, 1958, Ser. No. 779,181 1 Claim. (Cl. 36-42) This invention generally relates to replaceable top lifts for womens shoes and is more specifically concerned with an improved attachment of the sort designed for detachably mounting a top lift on a heel base in which there has been previously fitted a socket.

111 the shoe industry numerous inventions have been developed for providing womens shoes with detachable or replaceable top lifts. Many of these involve a top lift fitted to a base of some sort which frictionally engages a socket, prefitted within the body of the heel. It is desirable that the lift should be fitted snugly to the heel with a constant degree of frictional engagement after having been once assembled, otherwise the lift may become loose and pull or drop off.

In shoes where the detachable top lift has a resilient stem or post frictionally engaging the walls of the socket, a certain amount of compression of the stem takes place when it is inserted into a tubular socket and it is often found that this stem becomes permanently deformed or set in slightly contracted condition never returning to its original size and therefore losing some of its frictional holding power.

While the change that take place may be relatively small they are nevertheless sufficient to prevent a snug fit in the continued wear of the heel. Therefore, it is an object of this invention to provide in womens shoes a replaceable lift that will produce no appreciable change in fit even after being assembled with the heel and its stem forcibly inserted in the receiving socket.

'It is another object of this invention to provide in womens shoes a detachable top lift having a resilient post or stem which will not become deformed to any appreciable extent under all conditions of wear and treatment.

The post may be formed by folding a blank of resilient sheet metal into a triangular tube, the free edges butting along an apex ofthe triangle. It is a feature of this invention that a longitudinal rib be formed on the exterior of one or two of the sides of the tube so that they will frictionally engage the walls of the socket and stiffen the tube at the same time. It has been found that the presence of the ribs substantially eliminates any permanent deformation of the post and the snug fit is not at all affected by compression required for the insertion of the stem of the top lift.

These and other objects and features will more readily appear from a detailed discussion of a preferred embodiment of the invention, reference being made to the accompanying drawings, in which FIG. 1 is a plan view of the blank from which the post is drawn and folded,

FIG. 2 is a longitudinal section taken along the line 2-2 of FIG. 1,

FIG. 3 is a cross section taken along the line 33 of FIG. 1,

FIG. 4 is a perspective of the blank as it appears after the prongs have been offset,

FIG. 5 is a longitudinal section showing the top lift and post assembly inserted in the socket of a heel, and

FIG. 6 is a cross section taken along the line 5--5 of FIG. 5 and on an enlarged scale.

In the drawings 10 represents a heel base of a womans shoe and this may be made from wood, plastic or the like in the usual manner. A hole is drilled or otherwise fashioned from the tread face of the heel up into the heel base for a substantial distance, and a metallic socket 12 of generally triangular cross section is then forced permanently into the hole. An adhesive may be applied between the socket and the walls of the hole to insure a firm and fixed setting of the tubular socket within the heel.

Into the socket is inserted a hollow post or stem 14, of triangular cross section, being somewhat shorter than the socket but having peripheral dimensions slightly exceeding the inside dimensions of the socket 12. A top lift 16 of leather, nylon or some such material may be secured to the base of the post 12 by means of claw-like prongs 18 that are formed integral with the post in a manner that will now be described.

-In FIGS. 1-3 is shown a blank 20 which may be conveniently stamped and cut from sheet steel or other resilient metal. The blank is formed with three depending prongs 18 which are initially fiat but subsequently provided with offsets 26, as shown in FIG. 4. A pair of slots 22 are cut in the blank, spaced from and parallel to one another, and extend partially lengthwise thereof.

Pressed into the blank between the slots and the wide margin thereof are a pair of elongated ribs 28 running parallel to the slots and rounded in cross section. Typical dimensions of the rib may be from .015" to .020" in height from the face of the blank, and .040" wide with a length about equal to that of the slot.

The blank 20 is then folded into a tubular stem having a triangular cross section substantially as represented by the post 14. The fold is made lengthwise along both the slots 22 so that these slots will appear at two of the corners of the post with the free edges of the material butting along the third corner. The ribs 28 are now centrally located on the outer faces of the two abutting sides which are joined to define a triangle with the unribbed side which may be considered as forming the base of the triangle.

To complete the assembly the top lift 17 is attached to the post 14 by means of the prongs 18 and the post inserted into the socket where it is firmly seated. As seen in FIG. 6 the ribs 28 frictionally engage the inner walls of the socket 12.

When a post having flush sides and a gap between the free edges thereof is used to engage the socket it has been found by inspection that the post, once inserted into the socket, is compressed and does not return fully to its original shape being as much as .015 of an inch smaller than its original size and accordingly losing much of its original snug fit. This problem the present invention has overcome by the unobvious expedient of bringing the free edges butt together and forming longitudinal ribs along the post to engage the socket and stiffen the sides of the post in which they are formed. A post made in accordance with the present invention despite the compressive force of insertion suffers a negligible reduction in overall thickness, something in the order of only .001 of an inch in contrast with .015 of an inch previously encountered. For most practical purposes therefore deformation from compression has been eliminated by the ribs of the present invention and no longer poses a problem.

The use of adhesive is not necessary to hold the tubular socket 12 in place in the heel if the socket is driven Patented Nov. 13., 1962 into a slightly under-size bore in the heel, or in case the socket is cast into a heel having a metal body or section.

Having thus disclosed my invention and described in detail an illustrative manner of practicing it, I claim as new and desire to secure by Letters Patent:

In a replaceable top lift for womens shoes, a tubular stem of sheet steel, triangular in cross section and longitudinally slotted thus defining three Walls of the stem of which two make edge contact at a corner of the stem, the said contracting walls each having formed therein an outwardly projecting elongated rib running longitudinally and parallel to the corner slots and tapering at both ends and merging into the surface of the wall in which it is formed, thus stiffening the individual ribbed 4 walls of the stern longitudinally and also reducing deformation of the stem when inserted in a heel.

References Cited in the file of this patent UNITED STATES PATENTS 1,844,248 Gentile et a1. Feb. 9, 1932 1,947,840 Fitzsimrnons Feb. 20, 1934 1,995,058 Fitzsimmons Mar. 19, 1935 2,006,401 Maccarone July 2, 1935 2,111,314 Critchley Mar. 15, 1938 2,875,532 Fitzsimmons Mar. 3, 1959 FOREIGN PATENTS 815,336 France Apr. 5, 1937 

